Animals are killed to produce commercial meat, such as beef, lamb and pork, and are hung on a conveyor so as to move along a processing line. On the conveyor, the killed hanging animal is gutted and skinned as early processing steps. The resulting carcass moves forward along the processing line, but may carry contamination on the surface of the carcass from earlier processing steps such as the process of hide removal where hair and mud can fall off onto the carcass. The contaminants may include feces and bacteria.
The present practice, which is mandated by the U.S. Department of Agriculture, is to cut off the surface material upon which the contamination lies. This requires individual handwork and results in loss of otherwise useful meat and/or fat material from the carcass.
The U.S. Department of Agriculture does not approve of washing down the contamination off of the carcass because this process spreads the contamination and/or bacteria in it. Uncontrolled high-pressure spray could deteriorate the meat and spread the contamination. Vacuum alone is not satisfactory because it leaves some of the contamination and/or bacteria behind.